The rising tide of multidrug-resistant (MDR) pathogens ensures that the need for new antibiotics will continue to grow. This has led to antimicrobial peptides (AMPs) being considered as an alternative to conventional antibiotics, due to their potent and broad antimicrobial activity. The mode of AMP action is not fully understood, but their major targets are believed to be the cytoplasmic membrane and intracellular molecules (Pieters et al., Protein Pept Lett 16:736-742, 2009; and Nicolas, FEBS J 276:6483-6496, 2009). It is thought to be difficult for bacteria to develop resistance to antimicrobial peptides, because most AMPs kill bacterial cells quickly (Chan et al., Biochim Biophys Acta 1758:1184-202, 2006). Although small cationic peptides have a number of potential advantages as therapeutics, in vivo proteolysis and insufficient efficacy in animal model raise potential issues for clinical use.